As one of braking/driving force control apparatuses for a vehicle, such as an automobile, there has conventionally been known a driving force control apparatus, as disclosed in Japanese Unexamined Patent Application No. HEI9-309357 for example, for performing a distribution control of driving force applied to right and left wheels so as to exert a required yaw moment to a vehicle. Further, there has already been known a braking force control apparatus that controls a vehicle braking/driving force and yaw moment by controlling braking forces of wheels so as to secure a vehicle running stability. This braking/driving force control apparatus can enhance running stability of a vehicle.
In general, the vehicle braking/driving force and yaw moment can be controlled through the control of the braking/driving forces of the wheels. However, there is a limitation in the braking/driving force that can be generated by each wheel. Therefore, there may be the case in which the braking/driving force and/or yaw moment required to the vehicle exceeds the value attainable by the control of the braking/driving forces of the wheels. This situation is not considered in the above-mentioned conventional braking/driving force control apparatus, and it is necessary to make an improvement on this point.
When the target braking/driving force and/or the target yaw moment required to the vehicle exceed the values attainable by the control of the braking/driving forces of the wheels, the target braking/driving force and/or the target yaw moment may be modified such that the target braking/driving force and the target yaw moment after the modification take the values that are attainable by the braking/driving forces of the wheels and has as greater magnitude as possible. In that case, if the target braking/driving force sharply changes, the target yaw moment after the modification sharply increases or decreases and if the target yaw moment sharply changes, the target braking/driving force after the modification sharply changes, resulting in that the vehicle running stability deteriorates and an occupant or occupants of the vehicle feel a sense of incongruity.